Count-by Function. The weight meter can be programmed so that the display is rounded off to multiples of 1, 2, 5, 10, 20, 50 or 100. For example, if count-by 10 is selected, the meter will display 20 for an internal count of 15 to 24.Fixed Zero. The display can be shifted left to allow a fixed zero to be displayed to the right. This allows values up to 999,990 to be displayed.
Auto-zero Function. An auto-zero limit from 0 to 9 counts can be programmed to compensate for load cell drift. Whenever the meter comes to rest within that limit from zero, it will auto-zero. Entering 0 disables auto-zero.Two Tare Functions. The weight meter offers two types of tare: auto-tare and manual tare. In auto-tare, an input line is grounded by an external pushbutton. This causes the current weight, which is normally the empty weight of the container to be stored in memory as an offset. In manual tare, the tare value can be entered manually via the front panel or a computer. For instance, the tare value may be the stated empty weight of a truck or rail car. Pressing the Reset button on the front panel toggles the display between gross weight (total weight on the scale) and net weight (gross weight with tare subtracted).
An adaptive digital filter can be set for time constants from 17 ms to 9 s, yet responds rapidly to a change in input signal level exceeding a threshold value. The meter can automatically select the best filter setting for maximum noise rejection and minimum response time. Control and interface outputs can be derived from the filtered signal or, for quicker response, from the unfiltered signal. Display of peak value is standard in the Laureate series.
|d Cell Signal Conditioner||Full-Scale
|Error at 25°C|
|With DC Signal Conditioner||Full-Scale
|Error at 25°C|
|Accuracy, Load Cell Signal||Noise Rejection|
|Span Tempco||0.0030% of reading/°C||CMR, DC to 60 Hz
|Zero Tempco||Auto-zero||NMR at 50/60 Hz||90 dB with min filtering|
|Calibration Method||2 points using zero weight and known weight||--------||--------|
|Accuracy, DC Signal||Display|
|Span Tempco||0.01% FS ±1 count||Readout||5 digits, 7-segment, 14.2 mm (.56")|
|Zero Tempco||Auto-zero||Color||Red or green LED|
|Calibration Method||2 points using zero weight and known weight||Range||-99999 to +99999 or -99990 to +99990 (with fixed right-hand zero)|
|Count by 1, 2, 5, 10, 20, 50, 100 Four LED lamps|
|Voltage, std||85-264 Vac and 90-370 Vdc||5 Vdc||5 Vdc ±5%, 100 mA max|
|Voltage, opt||8-28 Vac and 9-37 Vdc||10 Vdc||10 Vdc ±5%, 120 mA max|
|Frequency||DC or 49-440 Hz||24 Vdc||24 Vdc ±5%, 50 mA max|
|Power isolation||Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
|Output isolation||50 Vdc to meter ground|
|Operating Temperature||0°C to 55°C||Technique||Concurrent Slope™ (Pat 5,262,780)|
|Storage Temperature||-40°C to 85°C||A-to-D Rate||60/s at 60 Hz, 50/s at 50 Hz|
|Relative HumidityProtection||95% at 40°C, non-condensingNEMA-4X (IP-65) when panel mounted||Output Update||56/s at 60 Hz, 47/s at 50 Hz|
|------------||---------------||Display Update||3.5/s at 60 Hz, 3/s at 50 Hz|
The five-digit meter can be scaled to display truck weight up to 99,999 lbs with 1 lb resolution or 999,990 lbs with 10 lb resolution. Accuracy is 0.01% of full scale at 25ºC. To avoid the effects of system-level noise, different filter settings as well as "count by" of 1, 2, 5, 10, 20, 50 or 100 with rounding are selectable.To read out net weight of the load, the truck can first be weighed empty, and this weight can be entered as tare at the push of a button in an auto-tare mode. Or the nominal tare value of the truck can be entered manually. Display of net weight or gross weight is at the push of a button. The gross weight and net weight can be alarmed, be transmitted to a computer via RS-232 or RS-485, or be transmitted via a 4-20 mA analog signal.
|In 4-wire connection, the excitation and sense lines are tied together. The meter can make ratiometric corrections for supply voltage variations, but not compensate for variations in lead resistance. This connection is often used with short cable runs.|
|In 6-wire connection, the sense lines are separate from the excitation lines, thereby eliminating effects due to variations in lead resistance. This allows long cable runs in outdoor environments with temperature extremes.|
|The DC signal conditioner board can be utilized to accept preconditioned 4-20 mA or 0-10 V scale signals. In two-wire 4-20 mA transmitter connection, the same two wires are used to apply voltage and carry the output current.|
|In a repetitive fill operation (as illustrated by example), a setpoint offset of -50 will allow a shutoff setpoint to be set for 1000 and actual shutoff to occur at 950 if it is known that 50 units will still flow following shutoff. An offset can also be applied to emptying operations.|